


Starved for the Salacious

by banana_thief



Series: Fire Emblem: Three Houses -- Explicit One Shots [1]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Sex, Desk Sex, Enemies to Lovers, Frottage, M/M, Male My Unit | Byleth, Minor Spoilers, Plot What Plot/Porn Without Plot, Post-Timeskip | War Phase (Fire Emblem: Three Houses), Roughness, Short One Shot, Smut, slight daddy kink
Language: English
Status: Completed
Published: 2019-12-05
Updated: 2019-12-05
Packaged: 2021-02-26 00:01:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,296
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21684175
Author URL: https://archiveofourown.org/users/banana_thief/pseuds/banana_thief
Summary: Mortified by rumors of the professor’s sexual exploits, Seteth attempts to rein in the young man but gets caught up in the allure instead.
Relationships: My Unit | Byleth/Seteth
Series: Fire Emblem: Three Houses -- Explicit One Shots [1]
Series URL: https://archiveofourown.org/series/1578007
Comments: 8
Kudos: 133





	Starved for the Salacious

Byleth was a strange one. Too quiet, too difficult to read, and when you conversed with him his eyes never really focused on you. There was an unmistakable mantle of mystery around him, and when he was alone, he appeared to lose himself—somewhere… immersed in his own psyche.

Byleth was a shadow of a man, all false smiles, arrayed in layers of black. Ever the charmer, but Seteth _knew_ better. Lady Rhea had trusted Byleth, and he _did_ save Flayn… and when Byleth returned to the monastery—his hair the hue of an Earth Dragon—Seteth accepted that he was, indeed, special. But Seteth didn’t like him, didn’t trust him. He couldn’t stand Byleth’s gentle façade, or that forlorn look in his eyes, because Seteth knew that impassive demeanor hid something dark. He watched Byleth on the battlefield, tall and strong, imposing… ruthless. He was a sound warrior, there was no doubting that, but it was the _way_ in which he killed that brought a chill to Seteth’s person. How Byleth’s eyes would vivify at that draw of blood, how he’d smile at the resounding crunch of a skull, revel in the screams. The way he wrung the grip of his sword—tense with anticipation. No wonder Dimitri took such a liking to Byleth—they were two of the same, deep down. The professor’s bloodlust was enough to repulse Seteth, but there was something else about him… his lascivious reputation. Rumors of his nightly endeavors—his rendezvous with his very own students—mortified the saint. He didn’t want his daughter around such… vulgarity. He was haunted by the thought; Byleth’s calloused hands on her, trailing her supple flesh, his voice low, filling her ears with prurient words…

Seteth felt his face grow hot. Rage no doubt. He inhaled, straightened his back, and smoothed his sleeves. He needed to set boundaries with the younger man. Correct his depraved ways. Professor or not, Earth Dragon or not, Byleth was an abhorrent ex-mercenary, and Seteth had to protect Flayn’s virtue.

It was late, but Seteth knew Byleth would be awake. He often caught the professor roaming the monastery’s dim corridors and jutting balconies. A true eccentric. But before Seteth could set him straight he had stop by his office to doublecheck if he had locked the door. He climbed the stairs and made his way down the hall, feeling rather on edge.

His door was shut, but a warm light leaked from the bottom threshold. Seteth, wary, opened the door. Byleth was waiting inside, sitting on the desk, swinging his legs. Seteth closed the door behind him, a little unnerved but thankful he didn’t have to comb the grounds.

“What brings you here, Byleth?” Seteth could hardly see his expression. The window casted moonlight onto his back, throwing most of his face into shadow despite the overhead candlelight. Seteth approached, cautious.

“Swords,” Byleth said, a nod over to the rack in the corner. “Care to duel?”

“Don’t be ridiculous,” Seteth scoffed.

“You’ve read all of these?” Byleth asked, his eyes scanning the bookshelves.

“Why are you here?” Seteth asked, growing irritated.

“I wanted to talk to you. I’ve noticed you’ve grown distant. More so. Did I do something to upset you?” He was still sitting on Seteth’s desk, all gloomy layers draped over bold mahogany wood. His ass firmly planted on important paperwork.

Seteth pursed his lips and approached the professor, but he was unsure of how to handle the situation.

“You’re always so tense, Seteth. Doesn’t that drain you?”

“Off my desk. Now.”

He did as commanded, with a small curl of his lip, his movement raining paper down onto the carpeted floor.

Seteth frowned. “I want you to stay away from Flayn.”

“But I’m her teacher.”

“You may carry on as such, but I don’t want you…”

Byleth leaned his ass against the table and crossed his arms across his chest. “Don’t want me to—what?”

“I know about your—your indiscretions.”

“Ah. I see,” Byleth said, pushing himself away from the desk. He closed what little distance between him and the older man. “I think you’re mistaken.” He was so close.

Seteth didn’t budge, never one to give in. “I don’t believe I am.”

“Seteth, when was the last time you came?”

“Pardon?”

“You’re so uptight, so… _bothered._ ”

“I am bothered by you, Byleth.”

“ _Oh,_ I love it when you say my name.”

Seteth bristled as heat blossom in his chest.

“If you know about me and my _indiscretions_ —” Byleth said, pulling a very tense Seteth into his arms, “maybe you should discipline me.” He connected their distance with a kiss, lips so soft and yielding to the older man that Seteth had no choice but to take over, devour him, hands snaking up to hold the back of Byleth’s head—drawing him closer—wanting more of his delectable tongue. Decades since Seteth had kissed anyone, amazed by how starved he was for it. Byleth moaned into his mouth, his hands gripped Seteth’s upper arms, allowed his tongue to be sucked. Seteth needed more, he turned Byleth, so his ass was against him. Seteth pushed the hair away from the nape of Byleth’s neck and kissed there—relishing the taste of salt and that intimate scent of musk.

“You’ve too many layers,” Seteth groaned, and drew the dagger from Byleth’s belt. An arm wrapped around Byleth’s neck, Seteth pulled the man back—just enough to guide the blade through the top of his clothing, freeing his toned chest. He heard Byleth gasp, felt him tense. Seteth threw the knife aside, skillfully lodging it into his violet floor. Seteth pressed his face into Byleth’s soft hair, nose hard against the back of his skull—he inhaled, intoxicated by the smell of him. His free hand slid down Byleth’s now naked stomach, past his waistband, and gripped his growing erection—surprised by its heat and girth. Scruples guide him for he might lose his mind, madness from the mere feel of this man pressed against him, trembling at his touch.

Byleth relaxed into Seteth, ass pressing into his hardness, head lolling back and resting in the crook of Seteth’s neck. Covered hands found their way up and back—gripping Seteth’s hair—pulling his circlet off and tossing it aside. Seteth kept stroking him, enamored by the soft moans of encouragement he elicited from the younger man. Byleth brought his hand over to Seteth’s lips—he forced two fingers inside his mouth, the well-worn leather of his glove glided over Seteth’s tongue. An awful sensation, but one that made him dizzy with arousal. He sucked on the vile fingers and quickened his hand. He heard warm laughter, a frustratingly pleasant sound, and Seteth instinctively shoved Byleth away, forcing him belly-first into the edge of the desk. The older man steadied his breathing—unaware of how erratic it grew—he smoothed out his hair and willed his erection away, failing miserably.

Byleth was doubled over the desk. His head slumped but he didn’t turn around. His pastel hair looked so soft in the candlelight. He straightened and Seteth flinched at the sound of fabric tearing. Byleth split the upper part of his clothing and casted it off—exposing well-crafted shoulders and a glorious back kissed with scars. He turned, smirking, with zeal in his eyes. Seteth had never seen that expression before, not from him, not from anyone. Seteth looked away, overwhelmed.

“No one’s watching, Seteth. Indulge a little. I know you want this. You need this just as much as I do, more so—probably.”

“And what exactly is this?”

“Pleasure. Does the church condone pleasure?”

“This is hedonism,” Seteth said swallowing, willing his eyes away from the professor’s stiff nipples.

Byleth laughed. “You’re ridiculous.” Much to Seteth’s dismay he returned to the desk, sitting. “Just fuck me already, _Daddy_.”

Seteth went crimson—ears, cheeks, neck—his cock responded to the words (much to his horror). He covered his mouth, tried to steady his spinning world, his shelves—whirls of color all around him.

“I’m going to take care of myself if you won’t,” Byleth threatened as he reclined back, smothering important documents with his perfect form.

Regaining some semblance of composure, Seteth climbed the well-crafted mahogany and straddled Byleth. “Who told you?” he asked, leaning over, taking in every plane of the professor’s face. Blue eyes, full lips. _Just breathtaking._

Byleth looked up at him, amused. “Told me what?”

“That I was a father.”

“Oh? I was just being kinky.”

Seteth’s stomach dropped.

“Why? Wait. Whose Daddy are—”

Seteth seized his lips. Anything to shut him up. Anything to keep his daughter safe. Anything to taste that mouth again. He pulled away, whispered, “I’m _your_ Daddy. Tonight.”

Stars in Byleth’s eyes, like he had reeled in the largest fish in Fódlan, like he had harvested the most prized squash, or mastered an impossible spell. Seteth would fuck him. He’d make those eyes roll back from pure adulterated ecstasy. _Kinky?_ Seteth had his work cut out for him, if the rumors were true about Byleth… It had been many, many moons but Seteth knew how to screw. Maybe Byleth was right, maybe he needed to… indulge, and if the younger man was so willing and offering—well, how could he say no?

Seteth lowered his head and took a nipple between his teeth. Byleth vaulted, eyes squeezed shut from the exquisite pain, mouth opened in a silent gasp. Seteth’s hands took over, freeing Byleth from the rest of his garments, wavering under the intensity of the younger man’s gaze. He bent, reached into one of his drawers and retrieved a vial of oil he kept hidden there (for the lonely nights).

Byleth raised an eyebrow. “What’s that?” He already knew.

Seteth responded by popping the cork and drizzling the cool lubricant onto Byleth’s erection.

Byleth watched, propped by the elbows, and trembled.

“Now stroke.”

Byleth did as demanded while Seteth unbuttoned. Not fully undressing, just enough to expose himself. He pulled his own erection out—slid it against Byleth’s. Wrapped a hand around both their cocks, stroking—tenderly twisting his palm around their throbbing, heated flesh. Byleth gritted his teeth, cheeks and chest flushed. Seteth could feel the younger man’s legs quake beneath his thighs. He maintained his steady tempo, thoroughly enjoying himself and Byleth’s fevered visage. Seteth slid his free hand up Byleth’s stomach, over hardened abdominals, up to his defined chest, up to his neck—where he gently wrapped his fingers around a delicate throat. A wild look from Byleth was the only permission Seteth needed. He squeezed. Byleth bucked into his hand, deliciously against his own cock, clearly relishing his lack of control.

“Seteth, _please_ ,” Byleth panted, voice caught in the palm of Seteth’s hand.

Seteth continued stroking, his balls tightened, he was so close. He released Byleth’s throat, and taking advantage of his gasp, shoved two fingers into the younger man’s mouth. Byleth groaned, sucked. One hand gripped the edge of the desk. His chest heaved—body responding to each and every stroke, tongue lapping at Seteth’s fingers. He closed his eyes, and Seteth trailed his slickened fingertips down to Byleth’s nipple—swirling it with saliva. Byleth came, spurting all over Seteth’s hand, which he then rubbed over their cocks, making sure to milk every last drop. Seteth dismounted Byleth, who rolled onto his side—sighing with satisfaction. But Seteth wasn’t done; he grabbed the professor, bent him over the desk, and kicked his legs apart. _His_ turn now. He’d inundate the corridors with Byleth’s obscene cries.

Byleth’s cheek pressed against the wood—documents already soiled with sweat and cum. Seteth forced one of his thighs up and onto the desk. He smeared more oil around Byleth’s hole, toying with it. He slowly pushed a finger in all the way to the knuckle. The professor cursed and squirmed but quickly relaxed around the digit. Seteth slipped another finger in—stretching him—so caught up in the visual, nearly coming... Growing ever impatient, Seteth lubed up his cock and positioned himself. He steadied his breathing, licked his lips, and eased in. Byleth gripped the table’s edge and sighed. Seteth savored the tightness from the younger man’s ass stretching around his cock. An obscene sensation. Utter bliss. He gripped Byleth’s supple hips, allowed him a moment, then slowly pulled out—half way—and then slowly pushed inside. Byleth writhed and muttered lovely nonsense as Seteth grabbed him by the shoulders and fucked him.

The saint didn’t realize how much he wanted this, needed this, needed Byleth. Absolutely fixated on the stories regarding the professor’s sexual prowess and conquests, Seteth was oblivious to the envy that surreptitiously grew and simmered away inside. He found Byleth insufferable, but here he was—pleasuring him, receiving pleasure in return… indulging.

Seteth grabbed Byleth’s arms and crossed them—pinning them down against his lower back—enjoying the initial resistance. Byleth moaned and cursed and pleaded. His voice heavy with desire and danger. Seteth couldn’t help but moan himself, enthralled by Byleth’s tight heat, and bodily surrender. The desk shook under their weight and efforts. Leaves of parchment fluttered down. The candles burned low. Seteth was close. Growing desperate. He pounded harder, deeper, fueled by Byleth’s deafening cries.

He came, so suddenly, shuddered, arms wrapped under Byleth’s limp weight—possessive. He dropped his forehead onto the younger man’s perspiring back. Kissed his spine.

Byleth whimpered as Seteth pulled out. He didn’t move—spent.

Seteth bit his bottom lip, satisfied, and proud of the wreckage sprawled before him. “Squeeze it out,” he whispered, “I want to see it.” He pulled Byleth’s ass cheeks apart and watched as cum emptied from his blushed hole—soiling the carpet.

 _Oh Goddess…_ this would never be enough.

**Author's Note:**

> Wrote this for my friend!  
> Thanks for reading, and thanks for the kudos! ♡


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